1. Field of the Invention
This invention relates to novel esters of halo-4-alkenoic acid compounds having pesticidal activity and methods of their preparation.
2. Description of the Prior Art
Esters of isovaleric acid are disclosed in U.S. Pat. No. 4,042,710, including 2- substituted isovalerates having the structural formula I: ##STR1## in which R represents an alkyl group of 1 to 16 carbon atoms (which may be branched), an alkenyl group of up to 6 carbon atoms, or a benzyl group optionally substituted by one or more halogen atoms.
U.S. Pat. Nos. 4,039,680; 4,062,968; and 4,058,622 all disclose esters having the general structure II: ##STR2## where R.sub.7 may be H, CH.sub.3, or CH.sub.2 CH.sub.3 ;R.sub.8 is H or CH.sub.3 ; R.sub.9 is CH.sub.3 ; Z is an alkyl group having from 1 to 3 carbon atoms.
Belgium Pat. No. 862,499 discloses a group of pyrethroidal esters which are characterized by the so-called "Pydrin alcohol" and a class of olefinic esters. The pesticidal phenoxy benzyl pentene carboxylates are prepared by esterifying a phenoxy benzyl alcohol with pentene carboxylic acid. According to the disclosure of Belgium Pat. No. 862,499, esters are prepared using a synthetic method from acids of the general formula III: ##STR3## wherein R.sub.4 =lower alkyl
R.sub.2 and R.sub.5 =H or an alkyl group having from 1-4 carbon atoms PA1 R.sub.6 and R.sub.7 =Cl or Br. PA1 R.sub.4 and R.sub.5 are independently H, a lower alkyl group having from 1 to 3 carbon atoms, polyhaloalkyl, haloalkyl, halogen, a lower alkenyl group having from 2 to 3 carbon atoms, a lower cycloalkyl group having from 3 to 5 carbon atoms, a lower cycloalkenyl group having from 3 to 5 carbon atoms, cyano, nitro, a lower alkoxy group having from 1 to 3 carbon atoms, arloxy, a lower alkylthio group having from 1 to 3 carbon atoms, arylthio, a lower alkylsulfinyl group having from 1 to 3 carbon atoms, arylsulfinyl, a lower alkylsulfonyl group having from 1 to 3 carbon atoms, arylsulfonyl, acylamido, or a lower dialkylamino group having from 1 to 3 carbon atoms; PA1 R.sub.6 is selected from the group consisting of: (1) cycloalkyl, alkenyl, branched alkenyl, or cycloalkenyl; or (2) a branched alkyl group having from 3 to 5 carbon atoms or an alkyl group having from 1 to 5 carbon atoms, with the proviso that R.sub.4 or R.sub.5 is other than hydrogen. PA1 Y is hydrogen, a lower alkyl group having from 1 to 3 carbon atoms, polyhaloalkyl, haloalkyl, halogen, cyano, nitro, a lower alkoxy group having from 1 to 3 carbon atoms, aryloxy, a lower alkylthio group having from 1 to 3 carbon atoms, arylthio, a lower alkylsulfinyl group having from 1-3 carbon atoms, arylsulfonyl, alkylsulfonyl, acylamido, or a lower dialkylamino group having from 1 to 3 carbon atoms; PA1 R.sub.8 is bromine or chlorine; and PA1 Z is oxygen, sulfur or its oxides, or methylene.
Belgium Pat. No. 860,687 discloses phenoxybenzyl haloalkenoate esters which are useful as insecticides and acaricides and have the following structural formula IV: ##STR4## wherein X is halogen, Y is halogen or CH.sub.3, Z is CN or ethynyl, and R.sub.1 is H or CH.sub.3.